Monday, August 30, 2010

Sakonnet Lighthouse under restoration

Rhode Island's Sakonnet Lighthouse is one of the most dramatic wave-swept towers in New England. It barely escaped destruction in the great hurricane of 1938, and it's taken a pounding in many coastal storms since it was built in 1884.

In January 2006, the nonproft Friends of Sakonnet Lighthouse received word that the group's application for $844,323 from the federal Transportation Enhancement Program had been approved. Along with bolt replacement, patching, and painting, there are plans to install better boat landing facilities at the lighthouse. The group has also privately raised close to $200,000 for restoration.

I received the following information in March 2009 from architect Deane Rykerson, based on a presentation given by John Wathne, a structural engineer and principal with Structures North Consulting Engineers of Salem, Mass.:
The structure is a cast-iron drum with an interior lining of brick. The structure tapers with thick flanged iron sheets engaging masonry. Although this is not truly a structural composite, the iron and brick interlock in such a way that one cannot move without the other moving. Brick growth, natural cement mortar harder than the bricks of the liner, and corrosion jacking on the inner faces and joints of the iron sheets, work together to announce the lighthouse's deterioration as a "paint problem" to passing recreation boaters. The primary problem with corrosion, and the primary consequence of paint failure, occurs at the joints of the panels of the drum, which are bolted but not welded and no longer watertight on the exterior.

Structures North decided to tear out the existing brick liner in vertical "lifts," dropping it into the void of the caisson below. This avoids the costs and environmental issues of disposal of the brick at this off-shore site. The cast-iron will be shot blasted on both sides then painted with a 3-part paint system (zinc-rich primer, epoxy, and polyurethane top coat). New brick will be brought to the site to replace the ruined liner.  John is full of admiration for his client group who has stayed with the project enthusiastically - even as its complications unfolded.
The contract for restoration was awarded in March 2010 to the Joseph Gnazzo Company of Union, Connecticut. Work began earlier this summer, and at this writing it's hoped the project will be completed by sometime in the fall. As part of the project, all the rust is being hydroblasted the rust off the tower's iron plates. All the rusted cast-iron bolts will be replaced by new stainless steel bolts. All the plates will be primed and painted.

I'm looking forward to seeing a gleaming, restored lighthouse in 2011!

3 comments:

  1. I was just there a few days ago and it was still shrouded in a cover. Hopefully the renovation will be finished in time for summer!

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  2. It was a major job, for sure. I hope it will be finished soon. I'll be cruising by there in late July.

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